On July 16, 2023, I discovered a population of P. taraxaci in the lawn of the Golden Municipal Airport (51.2972˚, -116.9828˚) in Golden, British Columbia, Canada. Phanacis taraxaci form smooth, fusiform, single or multichambered galls on the abaxial surface of T. officinale leaves (Fig 1A) that are approximately 1 cm in length (Bagatto et al., 1996) but multiple galls may coalesce forming a mass that can be 5 cm long (Beutenmüller, 1910). Globally, T. officinale is a host plant to a wide variety of plant parasites including species of bacteria, fungi, nematodes, mites, and insects (Stewart-Wade et al., 2002), but no other cynipid galler is known from the native (Eady & Quinlan, 1963) or non-native range (Beutenmüller, 1910; Weld, 1959; Nastasi & Deans, 2021).

Upon discovery of the P. taraxaci population in Golden, I dissected an infested leaf and found in each gall a small, yellow-white, oblong, motile larva (Fig 1B). The high activity and small size of the larvae suggests that they had not yet finished their development. I was unable to return to the site later in the season so I collected two highly infested leaves for rearing. I dried the galls in the open air in the field before placing them in a vial. I reared the galls in an unheated shed in Victoria, British Columbia, until spring 2024 but no adults emerged from the galls. I suspect that I collected the larvae too early in the season and that the larvae had not yet completed their development upon collection. I have deposited the two leaves in the Royal British Columbia Museum, Victoria, British Columbia.

The known range of P. taraxaci described in the literature includes six states in the USA: Illinois (Ashmead, 1897), Hawaii, Iowa, Minnesota, New York (Burks, 1979), and Pennsylvania (Nastasi & Deans, 2021); and four provinces in Canada: Ontario (Burks, 1979), Alberta, Saskatchewan (Paquette et al., 1993), and British Columbia (here). In recent years, the burgeoning community science platform iNaturalist.org has contributed more records of P. taraxaci in new states and provinces including Alaska, Colorado, Manitoba, Michigan, North Dakota, Oregon, Quebec, and Wisconsin (iNaturalist, 2024). The broad range of T. officinale in North America seems to be reflected in the few records of P. taraxaci in their invaded range. However, inconspicuous galls on a much-maligned invasive has likely led to the dearth of P. taraxaci records in North America. Community science platforms like iNaturalist are well poised to improve our understanding of the distribution of these gall wasps in North America.